Transverse momentum spectra,
d
2
σ
/
(
d
η
d
p
T
2
)
, of charged hadron production in
p
p
-collisions are considered in terms of a recently introduced two component model. The shapes of the particle ...distributions vary as a function of the c.m.s. energy in the collision and the measured pseudorapidity interval. As a result the pseudorapidity of a secondary hadron in the moving proton rest frame is shown to be a universal parameter describing the shape of the spectra in
pp
-collisions. In order to extract predictions on the double-differential cross sections
d
2
σ
/
(
d
η
d
p
T
2
)
of hadron production for future LHC-measurements the different sets of available experimental data have been used in this study.
The shapes of invariant differential cross section for identified
π
±
,
K
±
,
p
and
p
¯
production as a function of transverse momentum measured in
p
p
collisions by the PHENIX detector are analyzed ...in terms of a recently introduced approach. Simultaneous fits of these data to the sum of exponential and power-law terms show a significant difference in the exponential term contributions. This effect qualitatively explains the observed shape of the experimental
K
/
π
and
p
/
π
yield ratios measured as a function of transverse momentum of produced hadrons. A picture with two types of mechanisms for hadron production is presented. Universality of the power-law term behavior for
π
±
,
K
±
,
p
, and
p
¯
production is shown.
The transverse-momentum dependence of inclusive differential cross sections measured in various collider experiments for processes involving the production of long-lived charged hadrons was ...approximated by the sum of an exponential and a power-law function. The dependence of the parameters appearing in these functions on the colliding-particle energy and type was studied, and relationships between these parameters were established. A number of new regularities in the behavior of charged-particle spectra were discovered.
The shape of the invariant differential cross section for charged hadron production as a function of transverse momentum measured in various collider experiments is analyzed. Contrary to the behavior ...of produced charged kaons, protons, and antiprotons, the pion spectra require an anomalously high contribution of an exponential term to describe the shape.
Abstract
The morphological structure, size-age variability and dynamics of age-related fertility of producers of Baikal omul of pelagic, near-bottom and coastal morpho-ecological groups during the ...depressive state of the population were studied. There is an improvement in the indicators of the growth rate of fish, maturation and an increase in absolute individual fertility against the background of the dilution of the population and the release of the feeding area. A comparative characteristic of some morphological features of fish among morphological-ecological groups is given. The number of gill rakers on the first gill arch significantly distinguishes different morpho-ecological groups and ranges from 36 to 43 pieces for the near-bottom, from 40 to 46 pieces for the coastal and from 44 to 53 pieces for the pelagic morpho-ecological groups. It is noted that the spawning populations of the coastal and pelagic groups are mainly represented by young individuals. With age, the proportion of females increases in all groups. The largest indices of the pectoral, abdominal and anal fins, responsible for movement in the vertical plane, rotation and stop, are noted in the near-bottom group.
—
Data are presented on fish community structure in ponds and floodplain and mainland lakes in the southern taiga subzone of Western Siberia (within Tomsk region), where a total of 14 fish species ...have been recorded. The ordering of data on the fish biomass using a factor classification program has allowed us to distinguish three population groups, with one of them including three subgroups. Winter hypoxia is the most important among external factors determining the structure of fish communities. Its absence determines the presence of perch in the fish communities; in turn, the abundance of perch affects the abundance of other fish species. Therefore, the primary organization of the communities is determined by the environment and their secondary organization by the relationships between the species.
PDF
